Apparatus for molding insulators



Oct. 10, 1933. E. H. FISCHER 1,929,737

APPARATUS FOR MOLDING INSULATORS Filed Oct. 5, 1929 2 Sheets-Sheet l Imnentor k .1 Gttorneg |Pijl oct. 1o, 1933. E- H- FISCHER 1,929,737

Filed Oct. 5, 1929 2 Sheets-Sheet 2 fili f 7154!' nventor Pz/gene H fsczver Patented Get. 19,1933

unirse *s'rgfres PATENT cerros ,A

Y 1,929,737 ArrABA'rUs ron Mommer'NsULA'rons Eugene H. Fischer, Windsor,

Faience Company, Conn., a corporation of Connecticut The Hartford Conn., assigner vto Hartford,

Application October 5, 1929. .Serial No. 397,710

8 Claims.

of high tension insulators of the sorthaving av petticoat or skirt forming an interior chamber, and'pierced lugs on the exterior of the skirt and through which the lead-in wires are passed for the purpose of snubbing these wires; that is, to anchor the Wires to the insulator so that strains between the electrical connections within` the insulator are eliminated. Insulators of this type are used in street and road lighting. Heretoicre, it has been the practice tomakeV insulators of this sort by rst forming a body with `a petticoat devoid of lugs and then attaching metal pieces (or so-called lugs) to the formed body or insulator in separate operations. This old practice is open to numerous objections and particularly to the expense involved in the relatively slow process of separately making the insulator body and the metal pieces andthen securing the latter in place. It is alsoopen to the objection that the metal pieces, being secured to the body portion by screws, are apt to crack or break the insulator and thus defeat the function of the lugs which are to support and snub the lead-in Wires. It may be stated that, in forming high tension insulators of this kind, it is necessary to mold the material in a semi-plastic or putty-like state, and itis preferable to rotate the die which forms the interior chamber so as to obtain a lhomogeneous insulator of uniform density of the requisite dielectric strength.

An aim of the present-invention vis to provide an .improved method of and apparatus Yfor forming insulators having lugs or'ears, disposed as above described, all .in a single operation, the

operation being very rapidly carried out solas to` increase the rate of production and correspondingly lower the cost of manufacture. By proceeding in accordance with the present invention, in-

- sulators are formed which are of uniform densityk Y and homogeneity throughout, which havehigh dielectric strength and lower power losses, and which have integral lugs which are not apt to crack or break away from the body portion of the insulator. In short, better and stronger insulators are obtained at a lower cost.

Other objects will be in part obvious and in part pointed'out more in detail hereinafter.

The invention accordingly consists in the features of construction, combination 'of elements Fig. l0 is a like view of the and arrangement1 of parts which will be exemplied inthe construction hereinafter set forth and the scope of the application ofrwhich will be indicated in the appended claims.

In the accompanying drawings, wherein is shown, for illustrative purposes, one embodiments which the present invention may take:

Figure l is a perspective view of an insulator which may be formed by proceeding in accordance with the present invention;

Fig. 2` is a central "vertical sectional View through the apparatus, the plunger or die being vin elevation; y

Figs. 3, 4 and 5, respectively, show, in spaced relation, the die member in elevation with the surrounding molding section in cross section; the formed insulator in side elevation and in inverted position; and the bottom mold in vcenvtral section; Y

Fig.- 6 is a top view of the 32 being broken away;

Fig. '7 is a vertical, sectional view Athrough the parts shown in Fig. 6, this View being taken substantially on line 7-7 of that ligure; Fig. 8 is a perspective view of one-half of a securing member ;l Fig. 9 is a similar view oi one part of the upper mold section; lower part 'of the upper mold section; and

Fig` 11 is a horizontal sectional view taken on line ll-ll of Fig. 7.

' Referring to the drawings in detail, my improvedfapparatus is 'illustrated as being constructed for forming an insulator such as is of the many Y die member and v'the lsurrounding mold section, va part of the ring shown in Figs. l and l andin cross section in Fig. 2. This insulator is shown as having a cap or top portion A which terminates at its lower edge in a curved overhanging flange or cave B., Depending from the cap portion and spaced within the flange B is a petticoat or skirt C having an interior chamber D provided at its inner end with a recess E in which a socket (not shown) for the likeis adapted to be anchored. The overhanging ange B forms, between itselfk and the vupper end of the skirt or petticoat, anv annular i channel or -groove F. The insulatoris provided,

externally of the petticoat and beneath the flange; with a suitable number oflugs or ears G, two such projectionsl being illustrated in the present instance and being disposed on opposite sides of the petticoat. As previously stated, these lugs have heretofore been formed sepa- MEO rately and then stuck onto the previously formed insulator body. In the present instance, however, these lugs are formed integrally with the body portion and at the same time the body portion is formed so as to obtain a homogeneous and strong structure. It is, of course, understood that the specic insulator shown and described is herein referred to by way of illustration only, it being obvious that the improvements of the present invention may be employed for making plastic bodies of other types than that herein disclosed.

Referring now to my improved apparatus, designates a bottom mold for shaping the exterior of the top of the insulator, this mold being preferably formed of a suitable absorbent material, such as plaster of Paris, for reasons that are well understood in the art. This mold has a recess l0 shaped correspondingly to the top or cap portion A of the insulator and the exterior of the flange B and is substantially as deep as the height of the insulator from its top to the lower edge of the flange. The numeral l1 designates, generally, the die member for forming the chamber D and the recess E. This die member, in the present illustrative disclosure, is shown as being formed of two parts 11 and 11" for facility in manufacture of the die member. At the `upper end of the die member is an encircling tongue or rib 12, the purpose of which will be hereinafter described more in detail. The die member is suitably supported by a rotating member which is here shown as being in the form of a shaft 13. The lower end of this shaft has a threaded portion 14 which screws into a correspondingly threaded recess 15 located centrally in the top of the die member. The rotary supporting member or shaft 13 is suitably journalled for rotation and for movement in an axial direction, the manner in which the shaft is so carried not being illustrated, as any suitable arrangement may be provided. The shaft may be journalled in a vertically movable cross head of a press and may be rotated by gears or a belt. The cross head, together with the shaft, may be vertically recprocated by a crank oreccentric controlled by a foot pedal. For the purpose of breaking the vacuum in the bottom of therecess E, when the die is moved upwardly from the position shown in Figs. 2 and '7, the

lower end of the die may be vented to the atmosphere in any suitable or approved manner. For example, the portion 11 may have a through axial opening 16 leading from the bottom of the threaded recess 15 and the part 1l may have a port 17 leading from the recess l5 to the atmosphere. Within the vopening 16 is a movable stem 19 carrying a valve head 20 which may engage against the seat 21 in the lower end of the piece 11".

For the purpose of shaping the exterior of the petticoat and forming the channel F and the lugs G, there is provided a non-rotatable mold mounted for axial movement in unison with the die member 11. This mold, in the present illustrative disclosure, is of ring-like form so as to encircle the die in spaced relation and thus form a relatively-deep annular groove corresponding to the shape of the skirt. The mold has, in its interior periphery, recesses 27 corresponding in position-and size to the lugs G which are to be formed inthe insulator. In the drawings, this mold is `shown as comprising a ring-like body part 25 and a collar 26 at the lower end of the part 25 and connected to the latter for slight axial movement relative thereto. The lower surface of the collar 26 is transversely curved to correspond to the cross sectional shape of the channel F and the under side of the flange B. The recesses 27, corresponding to the lugs G, are in part formed in the member 25 andrin part in the collar 25. The collar 26is connected to the part by means of the bolts or screws 2Q, the heads of which have slight vertical movement in bores 30 in the upper' face of the part 25. The purpose of this arrangement is to permit of breaking of the vacuum along the exterior of the skirt when the die upper mold are moved upwardly, as will be hereinafter described more in detail. The part 25 has, on its interior wall and. at its upper end, a rabbet or enlarged bore which is adapted to rotatably receive the rib 12 of the die. Secured in any suitable manner, as by means of screws 31, to the upper end of the part 25 is a ring 32 which overhangs the rib 12. There is thus provided, in the upper mold, an annular groove or race way n which the rib 12 may rotate, the width or height of the groove being slightly greater than the height of the rib so that there is a slight axial movement between the die and the p For the purpose of preventing the uppe -cold from rotating with the die, there may be secured to the upper surface of the ring 32 s 'itable brackets 33 ,adapted to engage the cross of the press or other stationary part of the machine.

The operation of improved apparatus is briefly follows. The recess 10' in the bottom yith a material of which the insuned, such, for example, as plastic clay n wet state or of putty-like consistency. The l vt rn may be positioned upon the platform or bed 35 of the machine, the bed being diagrammatically shown in dotted lines in 2 particular construction thereof forms no part of the present invention. Then the assembly, including the continuously rotating die 1l, and the` non-rotatable upper mold are brought down Vunder pressure to the position show in Fig. 2 and, during this operation, the putty-iike'material is yforced by the die and under pressure upwardly into the annular' groove between the die and the upper mold and into the recesses 27 28 so as to form the petticoat and the integral lugs G. Also, the bottom of the upper die forms and shapes the channel It may be stated that the die l1 is rotated so that the material operated upon will not stick thereto andthe upper mold may be heated, as by means of a name directed thereagainst, for a like reason. After the insulator has thus been shaped, the die and the upper mold are-raised and, upon initial upward movement'of the die, the valve 2O will lag behind so as to vent the space between the lower end of the die and the bottom of the recess Also, owing to the lost movement between the heads of the bolts29Y and the bottoms of the recesses 36 in which those heads are located, the collar 2S will lag behind the part 25 so that the exterior wall of the petticoat is vented to the atmosphere and thus the vacuum, which would otherwise result, is broken. It will be observed that, in the presentillustrative disclosure, the upper mold is moved downwardly by the engagement of the rib l2 against the shoulder formed by the rabbet in the part 25, and that the mold is lifted with the die owing to the fact that the rib 32 overhangs Vthe rib 12, but it isto be understood .that my invention is not limited to this specific arrangement and, if desired, the

tically movable part or cross head in whichA the f shaft 13 is journalled against relative axial movement. There is sufficient play between the rib 12 and the groove in which it engages to permit of lubrication and to avoid undue friction and wear.

As many changes could be made in the above construction and many apparently widely different embodiments of this invention could be made without departing from the scope thereof, it is intended that allmatter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

t is also to be understood that the language used in the following claims is intended to cover all of the generic and specific features of the invention herein described and all statements of the scope of the inventionwhich, as a matter of language, might be said to fall therebetween.

I claim as my invention:

l. In a molding apparatus for manufacturing insulators, means for forming on the insulator a petticoat and integral lugs on the petticoat and comprising a rotating die, and a non-rotatable.

mold encircling said die and spaced therefrom so as to form a channel therebetween, said mold having on its periphery recesses in which the lugs are formed.

2. In a molding apparatus for manufacturing insulators, an axially movable rotating die, and a non-rotatable mold axially movable substantially in unison therewith, said die and mold forming an annular chamber for making a petticoat on the insulator and one of said members having recesses'for forming integral lugs on the petticoat.

3. In a molding apparatus for manufacturing insulators, a stationary mold having a recess corresponding to the exterior shape of one end of the insulator, an axially movable rotating die opposed to'said recess, and a non-rotatable mold about and axially movable substantially in unison with said die, said die and second mentioned mold forming an annular chamber for making a depending petticoat on the other end of said insulator, and said second mentioned mold having` grooves or recesses on its internal periphery and adapted to form integral lugs on the petticoat.

4. In a molding apparatus for manufacturing insulators, a stationary mold having a recess corresponding to the exterior shape of one end of the insulator, an axially movable rotating die opposed to said recess, and a non-rotatable mold about and axially movable substantially in unison with said die, said die and second mentioned mold forming an annular chamber for making a depending petticoat on the other end of said insulator, said second mentioned mold having its lower `end shaped to form an annular groove about the upper end of the petticoat, and said second mentioned mold also having recesses opening into its lower end and adapted to form integral lugs on said petticoat.

5. In a molding apparatus for manufacturing insulators, a stationary mold having a recess corresponding to the exterior shape of one end of the insulator, an axially movable rotating die opposedv to said recess, and a non-rotatable mold about said die and axially movable substantially in unison therewith, said die and second mentioned mold forming an annular chamber for making va depending petticoat on the insulator, said second mentioned mold having a body portion and a collar at one end adapted to move away from the bodyportion when the die and mold are withdrawn, said second mentioned moldV also having recesses formed in part in said body portion and in part in said collar for forming lugs on the petticoat.

6. In a molding apparatus for manufacturing insulators, a stationary mold having a recess corresponding to the exterior shape oi' one end of the insulator, a non-rotatable mold cooperating with and movable toward and from saidV stationary mold to press the insulator therein, and a continuously rotating die surrounded by and movable substantially in unison with said non-rotatable mold, said die being unthreaded, whereby the die may. be continually rotated during the entire pressing operation.

7. In a molding apparatus for manufacturing insulators, a stationary mold having a recess corresponding to the exterior shape of one endrof the insulator, a non-rotatable mold cooperating with and movable toward and from said stationary mold to press the insulator therein, and a continuously rotating die surrounded by and movable substantially in unison Awith said non-rotatable mold, said die being unthreaded, whereby'the die may be continually rotated during the entire pressing operation, said die and second mentioned mold forming an annular channel for making a depending petticoat on the insulator.

8. I a molding apparatus for manufacturing insulators, a stationary mold having a recess corresponding to the exterior shape of one end of the insulator, a non-rotatable mold cooperating with and movable toward and from said stationary ymold ,to press the insulator therein, and a continuously rotatingdie surrounded by and movable substantially in unison with said non-rotatable p mold, said die beingunthreaded, whereby the die may be continually rotated during the entire pressing operation, said non-rotatable mold having an annular body portion and an annular collar at the lower end of said body portion and forming a continuation thereof, and means for connecting said collar to said body portion for slight movement relative to the body portion so as to break the Vacuum when the die and mold are Withdrawn from'the insulator.

EUGENE H; FISCHER. 

